Organoruthenium chemistry

Organoruthenium chemistry is the

In its organometallic compounds, ruthenium is known to adopt oxidation states from -2 ([Ru(CO)₄]²⁻) to +6 ([RuN(Me)4]⁻). Most common are those in the 2+ oxidation state, as illustrated below.

• 
  1st generation Grubbs catalyst
• 
  Shvo catalyst
• 
  (cymene)ruthenium dichloride dimer
• 
  triruthenium dodecacarbonyl.
• 
  chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium
• 
  pentamethylcyclopentadienyl ruthenium dichloride dimer

Ligands

As with other late transition metals, ruthenium binds more favorably with soft ligands.^[3] The most important ligands for ruthenium are:

• halides, especially chloride.
• phosphines, especially triphenylphosphine
  .
• N-heterocyclic carbenes
  (NHCs).
• cyclopentadienyl ligands.
• various
  arenes and dienes
• carbon monoxide.
• hydride, notably in the Shvo catalyst.
• metal carbenes, notably in the Grubbs catalyst
  .

NHC ligands have become very common in organoruthenium complexes.[8]^[9] NHC ligands can be prepared with precise steric and electronic parameters, and can be chiral for use in asymmetric catalysis.^[10] NHCs, as strongly donating L-type ligands, are often used to replace phosphine ligands. A notable example is 2nd generation Grubbs catalyst, in which a phosphine of the 1st generation catalyst is replaced by an NHC.

Cyclopentadienyl ligands

The parent compound

Chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium features a reactive chloro group, which is readily substituted by organic substrates.

Arene and alkene ligands

One example of an Ru-arene complex is

Multinuclear organo-ruthenium complexes have been investigated for anti-cancer properties. The compounds studied include di-, tri-, and tetra-nuclear complexes and tetrara-, hexa-, and octa- metalla-cages.^[2]

Carbonyls

The main ruthenium carbonyl is

Ru₃(CO)₁₂ + 3 CO ${\displaystyle {\overrightarrow {\leftarrow }}}$ 3 Ru(CO)₅

Carbonylation of ruthenium trichloride gives a series of Ru(II) chlorocarbonyls. These are the precursors to Ru₃(CO)₁₂.

Organoosmium compounds

In the same

Important compounds, at least for academic studies, are the carbonyls such as triosmium dodecacarbonyl and decacarbonyldihydridotriosmium. The phosphine complexes are analogous to those or ruthenium, but hydride derivatives, e.g. OsHCl(CO)(PPh₃)₃, tend to be more stable.^[19]

References